File sharpening machine



y 1945- A. H. SWARTZWELDER 2,375,703

FILE SHARPENING MACHINE Filed May 5, 1944 2 Sheets-Sheet l I" -l V inventor y 945. A. H. SWARTZWELDER 2,375,703

FILE SHARPENING MACHINE Filed May 5, 1944 2 Sheets-Sheet Inventor flzwzv l7. SMMRTZWELZZER By 24m WWW 3% springs 36 for engagement beneath relatively thin files for stabilizing the device thereon.

It is thought that the operation of the machine will be readily apparent from a consideration of the foregoing. Briefly, with the carborundum wheel 30 turning at the desired speed, said wheel, through the medium of the handle 32, is swung in an arc across the face of the tooth of the file 3 which is being sharpened. When the operation has been completed the wheel 30 is swung clear of the'file and one of the shoulders 25 is engaged with the opposed forwardend of the adjacent arm 5 for feeding the assembly forwardly to the correct position for sharpening the next tooth. This is effected by the engagement of dog I3 and an associated file tooth, the pressure on one of members I5 eifected by the shoulder 25 serving to move the carriage 5 and its associated mechanism forwardly with respect to the position of the dog [3,

until the dog 34 has ratcheted over the next adjacent tooth. When the handle is again swung toward a central position, releasing the pressure of member l5, dog 34 holds the device against retrograde movement and the spring it. causes the dog I3 to ratchet over and engage behind the next adjacent tooth. The operation is then repeated. When the assembly is fed forwardly as above described, it is secured against retrograde movement by the dog 34 while the spring I6 m'oves the dog [3 forwardly for engagement with the next tooth of the file. Through the medium of the screw 24 the wheel 30 may be adjusted toward or away from the spindle it. Thus, the arc described by the wheel 30 about the spindle I8 may be controlled or regulated as desired for files having teeth of different degrees of curvature. This also adjusts the shoulders 25 relative to the arms I5 for regulating the length of each step of the forward feed of the assembly, it being apparent that the greater the distance of shoulders 25 from the ends of arms l5, the less distance carriage 5 will travel when the handle !3 is swung through its maximum path. Ob-' viously, the less the radius of each tooth for a file of a given width, the greater the linear distance the carriage 5 must travel to be properly positioned for grinding the next tooth. A retaining nut and washer 31 and 38, respectively, are provided on the spindle l8 for the members i9,

file sharpening machine constructed in accord-' ance with the present invention will be readily understood, and although a preferred embodiment of the device is as illustrated and described, it is to be understood that changes in the details of construction and in the combination and arrangement of parts may be resorted to which will fall within the scope of the invention as claimed.

What is claimed is:

j 1. A file sharpening machine comprising a rail for receiving thereon a file to be sharpened, a carriage slidable on the file and the rail, a manually operable support mounted for swinging movement on the carriage, a grinding wheel mounted on said support, and means engageable with the teeth of the file and operable by the support for feeding the carriage longitudinally relative to said file.

2. A file sharpening machine comprising a rail for receiving thereon a 'file to be sharpened, a carriage movable longitudinally on the file and the rail, said carriage including a base, a plate mounted for rotation on said base, an electric motor mounted for vertical swinging adjustment on said plate, a grinding Wheel operatively connected to said motor, and means on the base operable by the plate and engageable with the file for shifting the carriage longitudinally relative to said file.

3. A file sharpening machine comprising a base ALVIN H. SWARTZWELDER. 

